There have heretofore been proposed a variety of deodorizing substances for use being added to thermoplastic resins to impart deodorizing function to the molded articles thereof.
For instance, active carbon, inorganic filler such as porous zeolite or sepiolite, and titanium oxide utilizing photo-catalytic action, are capable of deodorizing a wide range of smelling components and have heat resistance lending themselves well for being melt-kneaded with the thermoplastic resin (patent document 1).
There has, further, been proposed a deodorant using ultrafine metal particles, such as a deodorant using, as an effective component, a colloidal solution of ultrafine metal particles obtained by reducing a metal ion-containing solution (patent document 2).
Further, the present applicant has proposed a resin molded article in which are dispersed ultrafine metal particles having an average particle diameter of 1 to 100 nm by heat-molding a mixture of a fatty acid silver salt or a fatty acid gold salt and a resin at a temperature higher than a temperature at which the fatty acid metal salt starts thermally decomposing but at a temperature lower than a temperature at which the resin thermally deteriorates (patent document 3). The applicant has, further, discovered that the ultrafine metal particles exhibit performance for adsorbing offensively smelling components such as methyl mercaptane, etc. and volatile organic compounds (hereinafter “VOC”) such as formaldehyde, etc. (patent document 4).    Patent document 1: JP-A-9-75434    Patent document 2: JP-A-2006-109902    Patent document 3: JP-A-2006-348213    Patent document 4: WO2006/080319